Transducer-holding block adapted to be mounted within a liquid-filled work-engaging roller

ABSTRACT

A block for holding an ultrasonic transducer (piezoelectric crystal), adapted to be mounted interiorly of a hollow liquidfilled work-engaging roller, is carried on the roller shaft and has a cap removably secured thereto. The cap has a recess in its block-engaging face, dimensioned to accommodate the transducer. A seal between the engaging faces of the block and cap prevents the liquid with which the roller is filled from coming into contact with the transducer.

United States Patent [72] Inventor Darwin D. Stombaugh Hammond, Ind.[21] Appl. No. 803,267 [22] Filed Feb. 28, 1969 [45] Patented Apr. 6,1971 [73] Assignee United States Steel Corporation [54]TRANSDUCER-HOLDING BLOCK ADAPTED TO BE MOUNTED WlTHlN A LIQUID-FILLEDWORK- ENGAGING ROLLER 2 Claims, 5 Drawing Figs.

[52] U.S. Cl 310/83, 73/675, 310/8.9,310/9.1 [51] Int. Cl H0lv 7/00 [50]Field of Search 310/8.3, 8.9, 8.1, 8.7, 9.0, 9.4, 9.1; 340/10; 73/71.5,67.5-67.9, (lnquired) [56] References Cited UNITED STATES PATENTS2,928,068 3/ 1960 Samsel et al. 340/10 2,972,068 2/1961 Howry et a1. 310/9. 1 X 3,094,636 6/1963 Gauld 340/10 3,113,287 12/1963 Renner 340/1OX3,178,678 4/1965 Grieg 340/10X 3,257,843 6/1966 Cowan 73/67.8X 3,277,43510/1966 Thompson et al. 340/10 3,442,119 5/1969 Cowan 73/675 3,453,4587/1969 Curran et a1 310/91 Primary Examiner-Milton O. HirshfieldAssistant Examiner-Mark O. Budd Attorney-Rea C. Helm Patented April 6,1971 3,573,515

- INVENTOR. 24 I 23 DARWIN 0. srouenuau TRANSDUCER-HOLDING BLOCK ADAPTEDTO BE MOUNTED WITHIN A LIQUID-FILLED WORK- ENGAGING ROLLER Thisinvention relates to the mounting of transducers used for ultrasonictesting and, in particular. to a mounting adapted to be placed inside ahollow liquid-filled work-engaging roller.

BACKGROUND OF THE INVENTION Transducer mountings of the general typeindicated above are known. One example is that made by Sperry ProductsDivision, Automation Industries, Inc. Difficulty has been experiencedusing these devices because of the tendency of the liquid (ethyleneglycol) to dissolve the cement bonding the transducer to a block carriedon the roller shaft. l have invented an improved transducer-mountingblock which overcomes the aforementioned difficulty. My mounting blockfully encloses the transducer and prevents contact therewith by theliquid filling the hollow roller.

BRIEF SUMMARY OF THE INVENTION In a preferred embodiment, I provide ablock of light material, e.g., Lucite synthetic plastic for mounting onthe shaft of a hollow roller which is adapted to be filled with liquidand to engage the product to be tested. I also provide a removable capto be secured to the block and form a recess or pocket in the under sideof the cap adapted to accommodate the transducer. Cooperative sealingmeans closes the joint between cap and block entirely around the pocket.When the cap is secured on the block, the transducer is fully protectedfrom contact by the liquid.

BRIEF DESCRIPTION OF THE DRAWINGS A complete understanding of theinvention may be obtained from the following detailed description andexplanation which refer to the accompanying drawings illustrating thepresent preferred embodiment. In the drawings:

FIG. 1 is a side elevation of a conventional ultrasonic testing rollerhaving my improved transducer-mounting block installed therein;

FIG. 2 is an end elevation thereof;

FIG. 3 and 4 are sectional views taken along the planes of lines lIIIIlof FIG. 2 and lV-IV of FIG. 1, respectively; and

FIG. 5 is an enlargement of a portion of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detailto the drawings and, for the present, to FIGS. 1 and 2 particularly, ahollow liquid-filled roller is journaled on a fixed shaft ll spanningstandards 12, by bearings 13. Roller 10 is mounted so as to make rollingcontact with a workpiece 14 (a length of pipe in the drawing) as ittravels lengthwise along a predetermined path such as a roller conveyor.Except for my invention, devices such as roller 10 are known (as wheelsearch units) and are commercially available, being manufactured bySperry Products Division of Automation Industries, Inc. one of which,suitable for my invention, is designated Sperry Style No. 50D263 WheelUnit.

My invention is the transducer unit 15, mounted on shaft ll within theroller I0, which is shown in greater detail in FIGS. 3 5. This unitcomprises a block 16 having its sides recessed as at 17 to accommodatespaced wing plates 18 welded onto shaft 11, whereby the block may besecured to the shaft by through bolts [9. The top face 20 of block 16 isat an oblique angle to the bottom and has fitted thereon a cap or cover21 secured by screws 22. The block 16 and cap 21 are conveniently formedfrom an acrylic resin such as Lucite plastic.

The undersurface of cap 21 which makes face to face contact with the top20 of block 16 has a recess 23 formed therein of size and shape adaptedto accommodate a transducer assembly 24 secured therein by screws 25with a layer of sealant such as silicone grease Q between the assemblyand the bottom of the recess to revent the entrapment of air. Sealinggrooves 26 in the con acting faces of the block and cover extend aroundthe recess 23 and an O-ring 27 seated therein prevents the access of theliquid-filling roller 10 to assembly 24.

A passage 28 drilled into block 16 from one side thereof intersects top20 within the area of recess 23 and permits leads from the assembly 24to be taken out to the exterior of roller I0 through a suitable passage(not shown) in shaft 11.

After the leads have been inserted through passage 28, the outer endthereof is plugged with silicone rubber to exclude liquid.

It will be understood that my invention provides a transducer mountingfor wheel search units having important advantages. In the first place,it is simple and inexpensive and may be manufactured by conventionalmachine practice. The principal advantage, however, is that my mountingwholly excludes the liquid filling the wheel or roller from damagingaccess to the transducer assembly.

I claim:

I. Ultrasonic testing apparatus comprising a fixed supporting shaft, ahollow ethylene-glycol filled work-engaging roller mounted on saidshaft, radial wing plates secured to said shaft in spaced-apartrelationship, a block between said wing plates extending radially fromsaid shaft, means fastening said block to said wing plates, a capremovably secured on said block and adjacent the periphery of saidroller, a recess in the underside of said cap, means sealing the jointbetween the cap and the block extending entirely around the area of therecess, a transducer, means for removably securing said transducer insaid recess, and a lead-wire passage extending from the exterior of saidblock to a point within said area.

2. Apparatus according to claim I in which said sealing means includes acircular groove surrounding the recess on the mating face of said cap, amatching groove on the mating face of said block, and a sealing ringseated in said grooves which seals said recess when said cap is securedto said block; an acoustic coupling of silicone grease between said capand said transducer; a silicone rubber plug sealing said lead-wirepassage from said liquid, and said cap and said block are both composedof an acrylic resin.

1. Ultrasonic testing apparatus comprising a fixed supporting shaft, ahollow ethylene-glycol filled work-engaging roller mounted on saidshaft, radial wing plates secured to said shaft in spaced-apartrelationship, a block between said wing plates extending radially fromsaid shaft, means fastening said block to said wing plates, a capremovably secured on said block and adjacent the periphery of saidroller, a recess in the underside of said cap, means sealing the jointbetween the cap and the block extending entirely around the area of therecess, a transducer, means for removably securing said transducer insaid recess, and a lead-wire passage extending from the exterior of saidblock to a point within said area.
 2. Apparatus according to claim 1 inwhich said sealing means includes a circular groove surrounding therecess on the mating face of said cap, a matching groove on the matingface of said block, and a sealing ring seated in said grooves whichseals said recess when said cap is secured to said block; an acousticcoupling of silicone grease between said cap and said transducer; asilicone rubber plug sealing said lead-wire passage from said liquid,and said cap and said block are both composed of an acrylic resin.